DESCRIPTION: In most disasters, the majority of victims receive their initial care at local hospitals. Thus, hospital-based disaster preparedness is critical to the management of mass casualty incidents, whether natural or man-made. Relatively little emphasis has been placed on hospital preparedness, however, and few data exist on the optimal structure of hospital disaster plans or the best methods for implementation. The specific aims are: (1) to obtain disaster plans from 40 hospitals; (2) to conduct a site survey at each hospital to validate the written plans and identify methods of implementation; (3) to identify outcome measures currently in use to assess hospital preparedness and performance during drills; (4) to define specific measurable characteristics that vary between plans and likely impact on overall preparedness; and (5) to develop a taxonomy for hospital-based disaster management plans, based on identified practice variation. While our long-term objective is to demonstrate associations between structural characteristics of disaster plans, implementation methods, and the effectiveness of the disaster response, this work will support subsequent progress by rigorously defining plan characteristics and performance indicators, demonstrating the measurability of these characteristics, and developing a classification system for hospital-based disaster management plans.